本文根据滦河三角洲地区的野外调查及收集的大量资料，以引滦工程对滦河水文的影响为基础，全面系统地分析、论述了三角洲自然环境的变化：三角洲海岸侵蚀后退，地下水位下降，滦河口盐水入侵，土壤盐渍化，河床冲刷、拓宽，河口淤积，预测了三角洲环境演变的趋势，提出了控制三角洲变化的决策。

According to field investigation and various collected information and data. I systematically analysed a series of delta environmental variations in the Luanhe River Delta after the water conservancy projects were built in the Luanhe River Basin. Since 1980, great changes of the river hydrology have taken place at the lower reaches of the Luanhe River. The runoff, sediment yield and water discharge decreased obviousiy. They caused delta environmental variations, such as coastal erosion, decline of ground water table, salty water intrusion, soil salinization, river bed erosion, deposition in the river courses in the estuary, and so on. I also tried to predict the evolution of the delta environment and put forward some proposals to control the environmental variations in the Luanhe River Delta.